Recently, the emergence of LLMs (Large Language Models) in the field of artificial intelligence has fundamentally changed the research paradigm. However, simply entering prompts into a ChatGPT web browser window has limitations when dealing with complex and vast amounts of biological data. LangChain is a powerful "LLM application development framework" that overcomes these limitations and organically connects LLMs to our research data, external APIs, and custom analysis scripts. It has become the de-facto standard for building AI-based agents or RAG (Retrieval-Augmented Generation) systems. From the perspective of a biotechnology and bio researcher, why is LangChain innovative? The answer lies in considering the research workflow we face daily. We constantly need to read and analyze the latest papers, extract necessary information from vast bio databases such as UniProt, ChEMBL, and PubMed, and run complex Python preprocessing code or analysis tools. LangChain allows us to connect all these processes into a single pipeline. For example, LangChain's "Chains" feature can seamlessly connect complex multi-step tasks, such as "Search for papers related to a specific protein in PubMed -> Extract candidate active inhibitors from the retrieved abstracts -> Send the chemical structure (SMILES) of each candidate to an external API to predict toxicity," with a single coding. Furthermore, by using the "Agents" feature, we can build an autonomous research assistance process where the LLM itself determines "I need to run the NCBI Clustal Omega tool to find out the function of this gene" or "I need to call the Foldseek API for structure search," selecting and executing the necessary tools appropriately. In summary, LangChain is a tool that gives LLMs, which were previously isolated, eyes, ears, and hands (the ability to execute external tools and local code). This allows researchers to move away from simple, repetitive data exploration and manual pipeline construction, and focus on higher-level hypothesis generation and experimental design.

A leading orchestration framework for developing LLM-based applications.

RAG System for Medical Information Based on the Latest PubMed/bioRxiv Literature: Load hundreds of the latest PDF papers related to a target disease within the laboratory and index them in a vector database. Subsequently, when a researcher asks a question in natural language, such as "What are the compounds and their concentrations that have been validated in recent mouse models during the study of inhibitors for a specific protein pathway?", LangChain will locate the precise experimental data from the relevant papers' text and tables, and generate a summary and answer along with the source page information.